function c2=c_two(X,K)

ker02=K;
ny=K.nu;
k=K.k;
mi=K.mu;
ker04=K_def('opt',ny,k+2,mi);
ker24=K_def('opt',ny+2,k+2,mi);
mX=mean(X);
n=length(X);
%sig2=sum((X-mX).^2)/(n-1);
%sig=sqrt(sig2);
sig=std(X);
%c1=c_one(w);
k=k+2;
ny=ny+2;
b_k=3.3175;
h_old=sig*b_k*n^(-1/(2*k+1));
[h0,pociter,iterace]=iter_bistef(h_old,X,ker04,30,0.0001);
gama04=(ker04.var/(ker04.beta)^2)^(1/(2*k+1));
gama24=(ker24.var/(ker24.beta)^2)^(1/(2*k+1));
h2=((2*ny+1)*k/(k-ny))^(1/(2*k+1))*(gama24/gama04)*h0;
psi2=psi_two(X,ker24,h2);
beta2=ker02.beta;
c2=abs(psi2)*beta2^2/4;
